With regard to solid preparations for oral administration, rapid disintegrating tablets in oral cavity which are rapidly disintegrated or dissolved when placed in oral cavity have been known.
As such rapid disintegrating tablets in oral cavity, there have been known, e.g., those containing an excipient and erythritol (Japanese Unexamined Patent Publication No. 2003-176242), those prepared by spray-drying a suspension containing an aqueous medium, calcium hydrogen phosphate and saccharides (WO 99/55373), those prepared by spray-drying a suspension containing an inorganic excipient and saccharides (Japanese Unexamined Patent Publication No. 2000-86537), those prepared by spray-drying a dispersion containing an inorganic antacid, a sugar alcohol and a disintegrating agent in an aqueous medium (Japanese Unexamined Patent Publication No. Hei 10(1998)-120554).
Besides the above, there have been disclosed a method for the production of oral dissolving tablets wherein saccharides such as xylitol, a pharmacologically active ingredient and water are mixed and made into tablets (Japanese Unexamined Patent Publication No. Hei 5(1993)-271054), an orally dissolving compression-molded product comprising granulates prepared by a fluidized-bed granulation of saccharides having a low molding property together with saccharides having a high molding property as binders (WO 95/20380), a rapid disintegrating solid preparation containing an active ingredient, a saccharide having an average particle diameter of 5 μm to 90 μm, a saccharide having an average particle diameter of 90 μm to 500 μm, a disintegrating agent and cellulose (WO 00/78292), a rapid disintegrating solid preparation prepared by spray-drying one sugar alcohol and a disintegrating agent, followed by dry tabletting (WO 02/69934), etc.